New mapping of subterranean Martian ice

This article describes a new process that has been used to map the ice that lies below Mars' surface, showing that the ice is much more patchy and variable than previously thought. The ice was first mapped by GRS (gamma ray spectrometer) instruments, but these were not very precise and can only show ice patches that are 300 or more miles wide. New images from THEMIS (thermal emission imaging system) instruments on the Mars Odyssey rover have shown that there is ice closer to the surface. This ice appears to be insulated by dust, allowing it to exist closer to the surface. The significance if this is that it may be easier to reach groundwater Igroung ice) in certain areas.